Improved device foe sharpening saw-teeth



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TO ALL WI-IOM I'I 4MAY CONCERN:

Be it known that I, HENRY DISSTON, of Philadelphia, Pennsylvania, have invented an improved Instrument for Sharpening Saw-Teeth; and I do hereby declare the following to be a full, clear, and exact description of the same.

My invention consists of an instrument, fully described hereafter, by which thc teeth of saws can be so led that the proper depth and length of the teeth must always be accurately preserved.

In order to enable others familiar with mechanism of this class to make and use my invention, I will new proceed to describe its construction and operation, reference being had to the accompanying drawing, which forms a part ot this specification, and in which- Figuro l is a side View of one form ot' my instrument for sharpening saw-teeth,

Figure 2 a plan view, and

Figure 3 a sectional view of the instrument, showing its application to the Vteeth of a saw.

A is a cylindrical tile, fitted to a suitable handle, B, and at or `near cach end of the tile is secured, in any suitable manner, a projecting rod, D, to which is fitted a sliding piece, E, to be secured, after adjustment, byla set-screw, c, the two sliding pieces being cbnnected togetherby or forming a part of a cross-bar, F, A eros'sbar, G, also extends from one rod, D, to the other, for a purpose described hereafter.

The mode of. using the instrument will be best observed on reference to tig. 3, where the cylindrical life A. is in theaet of cutting the hollow front ofthe tooth x, while the bar F rests on the top of the same tooth,'and,

as the cutting proceeds, is approaching the hollow front of the next tooth, x", which has been cu't' by the' file.4

The bar-G also rests on the top et' the tooth a1, and regulates the depth of the cut. When the bar F reaches the hollow front. of the previously-eut tooth fr', it is a certain indication that the tooth a: has been suiticiently filed, and that the instrument may be adjusted to operate on the tooth 2:, and thus tooth after tooth may be filed until all are sharpened. x t

It will be evident that the instrument serves as a perfect gauge, the distance ofthe barF fromi the file determining tho length of the teeth, and thc bar G deciding lthe depth of the eut to be made by the file. In other words, one finished tooth determines, by the aid of the instrument, the accurate finishing of the next tooth, while the shapes of the teeth are preserved, whatever may be the extent to which they are ilcd away.

The bar may be readily adjusted to snit teeth of dil'erent lengths, and although the bar Gis in the present instance shown as forming a permanent part oi' the instrument, it may be made adjustable thereon, so that the depthof the cut may be easily regulated. In large instruments the file may slide longitudinally, independently of the frame of the instrument, or a revolving cutter er stone may be substituted for the file.

Without confining myself to the specific arrangement or construction of parts herein described, I claim as my invention, and desire to secure by Letters Patent 1. The combination of a file or cutter, A, and a cross-bar or guide, F, arranged in respect to the cutter as to determine thc extent to which the latter shall penetrate the front of the saw-tooth, all substantially as described.

-2. The combination of the above, and a bar, G, or its equivalent, so arranged as to determine the extent `to which the cutter shall penetrate the saubladc.

3. The mode, Substantially as described, of rendering the bar F adjustable to and from the tile A.

In testimony whereof I have signed my name to this specicationin the presence of two subscribing witnesses.

HENRY Diss'roN,

Witnesses:

JOHN WHITE, W. J. R. DELANY. 

